“What is the therapy for negative thoughts?”

CBT or positive psychology

Cognitive behavioral and cognitive therapy styles would be a perfect fit for issues with negative thought processes.

Cognitive Behavioral Therapy (CBT) is a type of therapy that can help you identify unhelpful thinking styles and replace negative thoughts with more helpful, positive, and accurate ones.

CBT can be very effective for negative thoughts. Challenging those thoughts with positive ones are beneficial. Change your perspective.

See this link..
https://www.betterhelp.com/advice/therapy/three-common-cognitive-therapy-techniques/?network=g&placement=&target=&matchtype=b&ad_type=text&utm_source=AdWords&utm_medium=Search_PPC_c&utm_term=_b&utm_content=81347073590&network=g&placement=&target=&matchtype=b&utm_campaign=6459244691&ad_type=text&adposition=&gclid=CjwKCAjwiY6MBhBqEiwARFSCPq_yOvtq5u4lz9-N5GQ3Oa5ZCHHdDFf_g1hsHdOdtil4Qj90hYteSRoCnysQAvD_BwE

Cognitive Behavioral Therapy (CBT) is often the type of therapy that may be utilized to help decrease negative thinking. It also helps to understand different types of distorted thinking styles that may be occurring such as through frequently making assumptions, magnifying a situation, predicting the worst, overgeneralizing that each situation will happen similarly, or mind reading others, ect., so that way the thinking can be transferred to a more realistic form of thinking. If any negative thinking styles consists of self abuse, or internalized negative messages to the self, CBT may be utilized to debate reality for the individual to help identify strengths, facts and other healthy alternatives.